Electrical Characteristics of SiGe-base Bipolar Transistors on Thin-film SOI Substrates

Shu-Hui Liao,Shu-Tong Chang 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.61

This paper, based on two-dimensional simulations, provides a comprehensive analysis of the electrical characteristics of the Silicon germanium (SiGe)-base bipolar transistors on thin-film siliconon-insulator (SOI) substrates. The impact of the buried oxide thickness (TOX),the emitter width (WE), and the lateral distance between the edge of the intrinsic base and the reach-through region (Lcol) on both the AC and DC device characteristics was analyzed in detail. Regarding the DC characteristics, the simulation results suggest that a thicker TOX gives a larger base-collector breakdown voltage (BVCEO), whereas reducing the TOX leads to an enhanced maximum electric field at the B-C junction. As for the AC characteristics, cut-off frequency (fT) increases slightly with increasing buried oxide thickness and finally saturates to a constant value when the buried oxide thickness is about 0.15 µm. The collector-substrate capacitance (C CS) decreases with increasing buried oxide thickness while the maximum oscillation frequency (f max) increases with increasing buried oxide thickness. Furthermore, the impact of self-heating effects in the device was analyzed in various areas. The thermal resistance as a function of the buried oxide thickness indicates that the thermal resistance of the SiGe-base bipolar transistor on a SOI substrate is slightly higher than that of a bulk SiGe-base bipolar transistor. The thermal resistance is reduced by ∼37.89% when the emitter width is increased by a factor of 5 for a fixed buried oxide thickness of 0.1 µm. All the results can be used to design and optimize SiGe-base bipolar transistors on SOI substrates with minimum thermal resistance to enhance device performance.

Studying the Strain Effect on Silicon Atomic Wires

Shu-Tong Chang,Shu-Hui Liao,Hsiao-Chun Huang,Chee-Wee Liu,Chung-Yi Lin 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.6

The transport properties of a Si3 atomic wire system, which is formed by a Si3 cluster connected to two lithium electrodes with bias applied, is studied using the simulator Virtual NanoLab that is constructed based on the non-equilibrium Green’s function (NEGF) scheme. We investigated the Si3 atomic wire system under three strain conditions (tensile, compressive and shear). Different trends in the I-V characteristics are observed for the three cases at various applied biases. The transmission spectrum T(E, Vb), as a function of energy and applied biases, are analyzed. The interactions among eigenstates of the molecular projected self-consistent Hamiltonian (MPSH) strongly affect the transport properties of the system.

Impact of Stress Engineering on the Electron Mobility and the Balistic Current for Strained Si NMOSFETs

Shu-Tong Chang,Shu-Hui Liao,Wei-Ching Wang,Chung-Yi Lin,Jun-Wei Fan 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.2

The physical mechanisms of electron mobility and balistic drain curent enhancement by stress are investigated. From modified higher-order k·p band calculations, the stress-induced split of the conduction band edge and the effective mass change are quantitatively evaluated. It was experimentaly and theoreticaly demonstrated that the energy surface of 2-fold valeys in Si NMOSFETs on a (001) wafers is especially warped due to a uniaxial [110] stress, resulting in a lighter transverse effective mass of the 2-fold valleys parallel to the stress. The physical reasons for the warped subband structure and the abnormal mobility enhancement caused by the uniaxial stres are investigated. The rates of variation of the experimental electron mobility in NMOSFETs on wafers with (01) orientations undera <110> uniaxial stress as a function of the channel direction is theoretically studied. The limits of electron mobility enhancement and the effectiveness of stress enginering in enhancing the balistic drain current of NMOSFETs are also discussed.

Using low-coverage whole genome sequencing technique to analyze the chromosomal copy number alterations in the exfoliative cells of cervical cancer

Tong Ren,Jing Suo,Shikai Liu,Shu Wang,Shan Shu,Yang Xiang,Jing-He Lang 대한부인종양학회 2018 Journal of Gynecologic Oncology Vol.29 No.5

Objectives: We analyzed the chromosomal-arm-level copy number alterations (CNAs) in the cervical exfoliative cell and tissue samples by using the low-coverage whole genomic sequencing technique. Methods: In this study, we retrospectively collected 55 archived exfoliated cervical cell suspension samples and the corresponding formalin-fixed and paraffin-embedded tissue section samples including 27 invasive cervical cancer and 28 control cases. We also collected 19 samples of the cervical exfoliative cells randomly from women to verify the new algorithm model. We analyzed the CNAs in cervical exfoliated cell and tissue samples by using the low-coverage next generation of sequencing. Results: In the model-building study, multiple chromosomal-arm-level CNAs were detected in both cervical exfoliated cell and tissue samples of all cervical cancer cases. By analyzing the consistency of CNAs between exfoliated cells and cervical tissue samples, as well as the heterogeneity in individual patient, we also established a C-score algorithm model according to the chromosomal-arm-level changes of 1q, 2q, 3p, 7q. The C-score model was then validated by the pathological diagnosis of all 74 exfoliated cell samples (including 55 cases in model-building group and 19 cases in verification group). In our result, a cutoff value of C-score >6 showed 100% sensitivity and 100% specificity in the diagnosis of cervical cancer. Conclusion: In this study, we found that CNAs of cervical exfoliated cell samples could robustly distinguish invasive cervical cancer from cancer-free tissues. And we have also developed a C-score algorithm model to process the sequencing data in a more standardized and automated way.

Centralized Rolling Optimization Control for Active Power of Wind Farms

Shu Tong,Sung Kwan Kim(김성관),In Jung Hwang(황인정),Young Hoon Joo(주영훈) 대한전기학회 2019 대한전기학회 학술대회 논문집 Vol.2019 No.7

Characteristics of Microsatellites in the Transcript Sequences of the Laccaria bicolor Genome

( Shu Xian Li ),( Xin Ye Zhang ),( Tong Ming Yin ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.3

Multi-RIS Aided 3D Secure Precise Wireless Transmission

Tong Shen,Wenlong Cai,Yan Lin,Shuo Zhang,Jinyong Lin,Feng Shu,Jiangzhou Wang 한국통신학회 2022 Journal of communications and networks Vol.24 No.5

In this paper, multiple reconfigurable intelligent surfaces (RIS) aided secure precise wireless transmission (SPWT) schemes are proposed in the three-dimensional (3D) wire- less communication scenario. Unavailable direct path channels from transmitter to receivers are considered when the di- rect paths are obstructed by obstacles. Then, multiple RISs are utilized to achieve SPWT through the reflection path among transmitter, RISs and receivers in order to enhance the communication performance and energy efficiency simulta- neously. First, a maximum-signal-to-interference-and-noise ratio (MSINR) scheme is proposed in a single user scenario. Then, the multi-user scenario is considered where the illegitimate users are regarded as eavesdroppers. A maximum-secrecy-rate (MSR) scheme and a maximum-signal-to-leakage-and-noise ratio (MSLNR) are proposed. The former achieves a better secrecy rate (SR) performance but incurs a higher complexity. The latter has a lower complexity than the MSR scheme with an SR performance loss. Simulation results show that both single- user scheme and multi-user scheme can achieve SPWT which transmits confidential message precisely to location of desired users. Moreover, MSLNR scheme has a lower complexity than the MSR scheme, while the SR performance is close to that of the MSR scheme.

Association of Measures of Glucose Metabolism with Colorectal Cancer Risk in Older Chinese: A 13-Year Follow-up of the Guangzhou Biobank Cohort Study-Cardiovascular Disease Substudy and Meta-Analysis

Shu Yi Wang,Wei Sen Zhang,Chao Qiang Jiang,Ya Li Jin,Tong Zhu,Feng Zhu,Lin Xu 대한당뇨병학회 2024 Diabetes and Metabolism Journal Vol.48 No.1

Background: Abnormal glucose metabolism is a risk factor for colorectal cancer (CRC). However, association of glycosylated hemoglobin (HbA1c) with CRC risk remains under-reported. We examined the association between glycemic indicators (HbA1c, fasting plasma glucose, fasting insulin, 2-hour glucose, 2-hour insulin, and homeostasis model of risk assessment-insulin resistance index) and CRC risk using prospective analysis and meta-analysis.Methods: Participants (<i>n</i>=1,915) from the Guangzhou Biobank Cohort Study-Cardiovascular Disease Substudy were included. CRC events were identified through record linkage. Cox regression was used to assess the associations of glycemic indicators with CRC risk. A meta-analysis was performed to investigate the association between HbA1c and CRC risk.Results: During an average of 12.9 years follow-up (standard deviation, 2.8), 42 incident CRC cases occurred. After adjusting for potential confounders, the hazard ratio (95% confidence interval [CI]) of CRC for per % increment in HbA1c was 1.28 (95% CI, 1.01 to 1.63) in overall population, 1.51 (95% CI, 1.13 to 2.02) in women and 1.06 (95% CI, 0.68 to 1.68) in men. No significant association of other measures of glycemic indicators and baseline diabetes with CRC risk was found. Meta-analyses of 523,857 participants including our results showed that per % increment of HbA1c was associated with 13% higher risk of CRC, with the pooled risk ratio being 1.13 (95% CI, 1.01 to 1.27). Subgroupanalyses found stronger associations in women, colon cancer, Asians, and case-control studies.Conclusion: Higher HbA1c was a significant predictor of CRC in the general population. Our findings shed light on the pathology of glucose metabolism and CRC, which warrants more in-depth investigation.

Protein profiling predicts the response to anthracycline and taxanes based neo-adjuvant chemotherapy in breast cancer

Shu Wang,Houpu Yang,Jiajia Guo,Miao Liu,Fuzhong Tong,Yingming Cao,Bo Zhou,Peng Liu,Lin Cheng,Fei Xie,Deqi Yang,Jiaqing Zhang 한국바이오칩학회 2011 BioChip Journal Vol.5 No.1

Neo-adjuvant chemotherapy for breast cancer substantially benefits patients who achieve pathological response. However, clinical or pathological response information can only be obtained a period of time after chemotherapy. The identification of novel bio-markers or the application of new technique that can be used to predict treatment response before che-motherapy would allow therapy to be tailored on an individual patient basis. The purpose of this study is to identify the chemo-sensitivity and chemo-resistance related proteins using antibody microarray profiling, and to develop a multi-protein predictive model for breast cancer. Total protein was extracted from core needle biopsy samples obtained from 15 patients before treatment with neo-adjuvant TA(combination of taxanes and anthracycline) chemotherapy. Protein profiling was analyzed by antibody microarray. 10 pati-ents were used as training set to develop the predictive model using the software PAM(prediction analysis of microarray). Another 5 patients were used as a validation set to test the model. In cross-validation, the mole-cular predictive model showed an accuracy of 90%, in independent validation, the model classified the cases with an accuracy of 80%. In conclusion, the proteomic predictive model has the potential to predict pathological response to neo-adjuvant TA chemotherapy.

Differential response to abiotic conditions, predation risk, and competition determine breeding site selection by two anuran species

Tong Lei Yu,Yan Shu Guo 한국통합생물학회 2013 Animal cells and systems Vol.17 No.2

Sympatry of species has been a central debate in ecology for decades but the mechanisms that allow coexistence are still heatedly disputed. The main paradigms include the importance of abiotic conditions, predation risk, and competition as determinants of community structure. In this study, we investigated oviposition-site selection of two anuran species, Asiatic toads (Bufo gargarizans) and dark-spotted frogs (Pelophylax nigromaculata), which coexist in southwestern China. We sampled the abiotic and biotic attributes of 36 B. gargarizans breeding sites and 34 adjacent unused sites, and 30 P. Nigromaculata spawning sites and 36 nearby unused sites. Our results showed that these two anuran species differed in the use of the main habitat types. B. gargarizans selected larger spawning sites with low levels of disturbance, high dissolved oxygen content, and the presence of fish. Conversely, P. nigromaculata preferred smaller waterbodies that were shallow, clear, and free of fish and B. gargarizans tadpoles. We conclude that differential habitat use and differences in response to abiotic conditions, predation risk, and competition, contributes to facilitating local coexistence and high species diversity in pond communities.